Containers and, in particular, open-mouth rigid containers, such as glass bottles or the like, are commonly subjected to post treatment wherein various coatings are applied to the outer surfaces of the container. Such coatings are applied, for example, to improve fracture resistance, impart lubricous properties and, in some cases, to color the containers. The coatings are applied by conventional techniques, such as dipping or by electrostatic deposition, and cured by heat treatment.
The containers are generally carried through the coating and curing stages on hangers suspended from a continuous conveyor, the containers being releasably engageable with the hanger. Furthermore, it is preferable that the containers be supported interiorly by the hanger, one such means of providing internal support for the container being disclosed in U.S. Pat. No. 3,777,875, assigned to the assignee of the present invention.
In the said patent, the hanger member terminates in a frusto-conical resilient member which is forcibly inserted into the container mouth and frictionally engages the inner surface thereof whereby the container may be carried through the various processing stages. The container is released by forcibly disengaging the resilient insert by the downward stroke of a cylindrical sleeve-like member actuated by a cam means.
This container transporting means suffers, however, from the disadvantage that the resilient frusto-conical member must be sized to engage a container mouth of a particular diameter, with the consequence that the resilient members must be changed to accommodate containers having only slightly differing mouth dimensions. Moreover, the forcible engagement and disengagement of the resilient member results in increased wear and frequent replacement of the resilient member. Additionally, the containers must be accurately aligned with their respective hangers in order to assure proper engagement of the resilient member with the container mouth.